# uncompyle6 version 3.2.3
# Python bytecode 3.6 (3379)
# Decompiled from: Python 3.6.8 |Anaconda custom (64-bit)| (default, Feb 21 2019, 18:30:04) [MSC v.1916 64 bit (AMD64)]
# Embedded file name: site-packages\urllib3\util\request.py
from __future__ import absolute_import
from base64 import b64encode
from ..packages.six import b, integer_types
from ..exceptions import UnrewindableBodyError

ACCEPT_ENCODING = "gzip,deflate"
_FAILEDTELL = object()


def make_headers(
    keep_alive=None,
    accept_encoding=None,
    user_agent=None,
    basic_auth=None,
    proxy_basic_auth=None,
    disable_cache=None,
):
    """
    Shortcuts for generating request headers.
    
    :param keep_alive:
        If ``True``, adds 'connection: keep-alive' header.
    
    :param accept_encoding:
        Can be a boolean, list, or string.
        ``True`` translates to 'gzip,deflate'.
        List will get joined by comma.
        String will be used as provided.
    
    :param user_agent:
        String representing the user-agent you want, such as
        "python-urllib3/0.6"
    
    :param basic_auth:
        Colon-separated username:password string for 'authorization: basic ...'
        auth header.
    
    :param proxy_basic_auth:
        Colon-separated username:password string for 'proxy-authorization: basic ...'
        auth header.
    
    :param disable_cache:
        If ``True``, adds 'cache-control: no-cache' header.
    
    Example::
    
        >>> make_headers(keep_alive=True, user_agent="Batman/1.0")
        {'connection': 'keep-alive', 'user-agent': 'Batman/1.0'}
        >>> make_headers(accept_encoding=True)
        {'accept-encoding': 'gzip,deflate'}
    """
    headers = {}
    if accept_encoding:
        if isinstance(accept_encoding, str):
            pass
        else:
            if isinstance(accept_encoding, list):
                accept_encoding = (",").join(accept_encoding)
            else:
                accept_encoding = ACCEPT_ENCODING
            headers["accept-encoding"] = accept_encoding
        if user_agent:
            headers["user-agent"] = user_agent
        if keep_alive:
            headers["connection"] = "keep-alive"
        if basic_auth:
            headers["authorization"] = "Basic " + b64encode(b(basic_auth)).decode(
                "utf-8"
            )
        if proxy_basic_auth:
            headers["proxy-authorization"] = "Basic " + b64encode(
                b(proxy_basic_auth)
            ).decode("utf-8")
        if disable_cache:
            headers["cache-control"] = "no-cache"
        return headers


def set_file_position(body, pos):
    """
    If a position is provided, move file to that point.
    Otherwise, we'll attempt to record a position for future use.
    """
    if pos is not None:
        rewind_body(body, pos)
    else:
        if getattr(body, "tell", None) is not None:
            try:
                pos = body.tell()
            except (IOError, OSError):
                pos = _FAILEDTELL

            return pos


def rewind_body(body, body_pos):
    """
    Attempt to rewind body to a certain position.
    Primarily used for request redirects and retries.
    
    :param body:
        File-like object that supports seek.
    
    :param int pos:
        Position to seek to in file.
    """
    body_seek = getattr(body, "seek", None)
    if body_seek is not None:
        if isinstance(body_pos, integer_types):
            try:
                body_seek(body_pos)
            except (IOError, OSError):
                raise UnrewindableBodyError(
                    "An error occurred when rewinding request body for redirect/retry."
                )

        if body_pos is _FAILEDTELL:
            raise UnrewindableBodyError(
                "Unable to record file position for rewinding request body during a redirect/retry."
            )
        else:
            raise ValueError(
                "body_pos must be of type integer, instead it was %s." % type(body_pos)
            )
